Newbetuts

Example of two open balls such that the one with the smaller radius contains the one with the larger radius.

Does there exist a non-abelian group with roots?

Irrationality or Rationality of p+q given that pq=1

Do we have always $f(A \cap B) = f(A) \cap f(B)$? [closed]

Continuous partials at a point but not differentiable there?

Good pair vs. cofibration

A congruence involving Fibonacci polynomials

Nonabelian infinite nilpotent groups

Give an example of a non compact Hausdorff space such that $\Delta$ is closed but $Y$ is not Hausdorff

A congruence involving Chebyshev polynomials

Gluing Lemma for Closed Sets: Infinite Cover Counter-Example

Convergence Counterexamples

Counterexample to Riemann sum limit

A smooth nowhere analytic function such that all derivatives are monotone

Given a bounded countable set, for all uncountable sets, does part of the uncountable set look the exact same as that countable set?

New posts in examples-counterexamples

Is an ideal finitely generated if its radical is finitely generated?

Do subgroup and quotient group define a group?

Is a continuous function locally uniformly continuous?

An example of a bounded, continuous function on $(0,1)$ that is not uniformly continuous

Is there a counter example for this statement?

Example of two open balls such that the one with the smaller radius contains the one with the larger radius.

Does there exist a non-abelian group with roots?

Irrationality or Rationality of p+q given that pq=1

Do we have always $f(A \cap B) = f(A) \cap f(B)$? [closed]

Continuous partials at a point but not differentiable there?

Good pair vs. cofibration

A congruence involving Fibonacci polynomials

Nonabelian infinite nilpotent groups

Give an example of a non compact Hausdorff space such that $\Delta$ is closed but $Y$ is not Hausdorff

A congruence involving Chebyshev polynomials

Gluing Lemma for Closed Sets: Infinite Cover Counter-Example

Convergence Counterexamples

Counterexample to Riemann sum limit

A smooth nowhere analytic function such that all derivatives are monotone

Given a bounded countable set, for all uncountable sets, does part of the uncountable set look the exact same as that countable set?